The unhappy neighbors of a housing development under construction in Maili have banded together once again, this time to stop the subdivision’s $300,000 drainage project.

The neighbors, who have been blocking crews from completing a concrete drainage structure this month, say the project will end up discharging polluted stormwater into the Mailiili Stream channel and undermine a healthy riparian area filled with wildlife.

“It’ll kill the environment of the stream,” said Michele Kuahine, who lives across the street from the nearly completed Hale Makana o Maili apartment complex.

Kuahine and about 15 of her neighbors were at the construction site Nov. 2 under a tent, holding vigil against the unfinished drainage project at the end of Kulaaupuni Street. Beyond the dead end is the channelized Mailiili Stream, which flows toward the ocean for a few hundred yards before meeting the sea on the north side of Maili Beach Park.

The residents say the project could ruin a natural estuary habitat where residents have fished and enjoyed viewing sea turtles, native birds and other creatures for generations.

“This is an irreplaceable natural resource that must be protected,” Kuahine said.

The drainage project is planned in part to serve the 52 units of the affordable-housing project Hale Makana o Maili, which is being built by the nonprofit Hawaiian Community Development Board.

The neighbors came together a year ago to oppose the proposed complex, saying its density threatened to overwhelm the rural neighborhood. And although a suit brought by the neighbors was dismissed in court, the complaint is still alive on appeal.

In the meantime, construction of the $22 million project continues, with a target completion date now about one month away.

Hawaiian Community Development Board Executive Director Kali Watson says the project — more than four years in the making — aims to help alleviate Hawaii’s homeless crisis, especially on the Leeward Coast.

Watson said the off-site drainage system was not part of the original design. At first, a pair of on-site “vegetative bio-filter basins” were planned to handle precipitation and keep runoff to a minimum.

However, during the review process, resident and city representatives asked the developer to address the chronic flooding situation on Kulaaupuni Street, he said.

Money was initially allocated in the city budget for the drainage project, but it didn’t make the final cut. The company decided to take care of it anyway, Watson said, proposing a drainage project that was ultimately reviewed and approved by the city.

“We were trying to be the good guys in this situation,” said Watson, former director of the Department of Hawaiian Home Lands. “They’re making it out like it’s going to be an environmental disaster, but it’s not.”

The dispute escalated when work crews — confronted on-site by Kuahine and asked for a work permit — produced a document with the wrong address. They were forced to stop.

“That shows how very underhanded this is,” said neighbor Lilly Cabinatan. “(Watson) has the right idea to build affordable housing, but now he’s going to pollute our stream. This is underhanded with a phony permit.”

Watson, however, said that the mistake was the city’s fault because the wrong address was put on the permit. A new permit was obtained from the city after the contractor pointed out the mistake.

Watson said the drainage project has been put on hold pending a resolution of the dispute. He said he’s also considering abandoning the effort and returning to the original on-site drainage plan.

“I don’t want a confrontation,” he said “That’s the furthest thing from what I want. It’s a good (housing) project that’s needed.”

As the standoff continues, inspectors with a handful of state and city agencies have come out to check out the situation. The state Department of Health has directed the developer to remove the 80 or so sandbags that were placed by crews in the streambed to prevent runoff from the excavation work.

Watson said he’s also been asked to look into whether he needs an additional permit from the U.S. Army Corps of Engineers.

Kuahine, who lives across the street from the new development, insists that flooding on the street is not a problem. She said the developer should be taking less severe measures to deal with the runoff from the housing project.

“No one should be able to come in so easily and destroy a place where the water, the fish, the crabs, the Hawaiian sea turtle, the Hawaiian stilt all live and were all here first,” she said.

Watson contends the real reason for the protest is trying to stop the project.

“It’s a new angle,” he said. “They’re trying to make it seem like an environmental thing.”

Kuahine denies the protest is about the housing project. She said she and her neighbors have been playing in and around the stream their entire lives — fishing, crabbing, riding a kayak out to the beach park. Now her own grandchild is experiencing and enjoying the same things.

“What I am protecting is my jewel in my backyard, in my small community, that, if allowed to be so carelessly destroyed, will be gone forever,” she said.